Recently a built-in antenna has been commonly used in a field of a radio communication device, particularly a portable transceiver.
A perspective view of a conventional folding portable transceiver is shown in FIG. 9.
Built-in antenna section 103 is disposed near hinge section 102 and close to coupling section 104. Keyboard side board 105, which is a first circuit board, is coupled with liquid crystal display side board 106, which is a second circuit board, via coupling section 104. Keyboard side board 105 is covered with first housing 107 having an input section at its surface. Liquid crystal display side board 106 is covered with second housing 108 having a display section.
An example of the portable transceiver having the structure mentioned above is disclosed in Japanese Patent Unexamined Publication No. 2003-8320.
In a case of built-in antenna section 103 disposed near hinge section 102 shown in FIG. 9, when portable transceiver 101 is opened and shut, an input impedance of built-in antenna section 103 changes.
In particular, when portable transceiver 101 is shut, current distribution concentrates and an impedance characteristic deteriorates because built-in antenna section 103 is close to coupling section 104. Therefore, it is difficult to work at a broadband.
The present invention provides a portable transceiver where a broadband of an antenna characteristic can be realized and efficiency is improved.